FLASH OF LIGHT from a neutrino strike triggers sensors in an artist's conception of a neutrino detector.
Image: Vault49
In Brief
- The neutrino is the oddest breed of fundamental particle. Neutrinos seem to defy all precedents set by better understood varieties of particles, such as electrons and quarks.
- Lightweight, shifty and exceedingly difficult to detect, neutrinos have been vexing experimentalists for decades.
- Even today fundamental properties of neutrinos remain up for debate. Some of the key questions pertain to the origin of their meager masses, the nature of neutrino antimatter and the number of neutrino species in existence, not to mention their penchant for switching identities on the fly.
- Uncovering the true nature of the neutrino may pave the way to a more unified theory of physics.
More In This Article
Few physicists have had the privilege of bringing a new elementary particle into the world. When Wolfgang Pauli hit on the idea of the neutrino in 1930, however, internal misgivings tempered his response. “I have done a terrible thing,” Pauli later told his colleagues. “I have postulated a particle that cannot be detected.”
The neutrino is indeed elusive—its ghostly nature allows it to slip through almost all physical barriers, including the materials that physicists use in their particle detectors. In fact, most neutrinos pass cleanly through the earth without so much as brushing against another particle. Yet Pauli's fears turned out to be slightly overblown: the neutrino can be detected—although doing so requires great effort and experimental ingenuity.
This article was originally published with the title Ghostly Beacons of New Physics.
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15 Comments
Add CommentI have 2 questions. When the authors say that neutrinos move at close to the speed of light shouldn't they specify a reference frame? Since neutrinos have mass and move at sublight speeds in every frame, cant a Lorentz boost "transform" left-handed neutrinos into right-handed neutrinos?
Reply | Report Abuse | Link to this"They [neutrinos] are the only electrically neutral matter particles". Last I checked, neutrons are matter and are also electrically neutral. What am I missing?
Reply | Report Abuse | Link to this1) In principle yes. But any reference frame accessible to us is far from the speed of light. So the statement is correct in all reference frames being of relevance for us. 2) No. Left- and right-handed refers to chirality here, not helicity. Chirality is a Lorentz-invariant quantity, and thus not altered by boosts. Only for massless particles moving at the speed of light helicity equals chirality.
Reply | Report Abuse | Link to thisParticle here refers to fundamental building blocks. Neutrons are made out of quarks which are themselves not electrically neutral. So a neutron doesn't qualify as a particle in this sense.
Reply | Report Abuse | Link to thisSteve,
Reply | Report Abuse | Link to thisThe neutron and neutrino are both uncharged subatomic particles. The neutron is a component of atoms whereas the neutrino is not. The neutron is held motionless in an atom while the neutrino is always in motion at the speed of light.The Neutron has a mass of about 1.67x10E-24, the electron has a mass of about 9.1x10E-28 and the neutrino has a mass of about 9.1x10E-34 (about one millionth the size of an electron), so you can see these particles go down in mass considerably from each other. The question is what makes up the mass, is it just a bundle of energy.
yeoldeanger
Debunking the likes of Sir Issac Newton, Einstein, my Science teachers,
Reply | Report Abuse | Link to thisWe have been led to believe that thunder is the after math or results of lightning when in fact the opposite is true!
Thunder (the collapse of air cells) creates the energy of what we call lightning.
Thunder happens first!
Sound travels much faster than light !
Three types of neutrinos have various masses, thus do they change their velocity successively?
Reply | Report Abuse | Link to thisIn AWT the superpartner of neutrino are photons, which are naturally short living particles due the decoherence.
Reply | Report Abuse | Link to thisI was confused by the upper graph using log distance.
Reply | Report Abuse | Link to thisThis obscures the cos nature of the oscillation; ie, the flavor is rotating. Also, the graph doesn't reconcile with the slow oscillation pie charts for the muon neutrino; is this because of mixing with the fast oscillations?
I read this article about neutrinos and was wondering if the authors (or any one else for that matter) could answer a few questions I have.
Reply | Report Abuse | Link to this1) Do neutrinos and photons interact? If so what are the effects of that interaction? Does a photon lose energy due to that interaction?
2) As I understand it, there are more neutrinos in the universe then any other particle and their density is greatest in the center of galaxies. If one were to conjecture that either the mass or gravitational effects of neutrinos was negative, then gravity and its effects would be reduced in those regions of the greatest neutrino density.
Thanks,
QuantumDyslexia
Forces of equal evolution interact with forces of equal evolution.
Reply | Report Abuse | Link to thisDark matter of outer space is made up of info cells of all earth. We are not made for this planet but are made of it. It is the reason for the familiar make up of life in times past.
If there is a nook or cranny any where in our universe that conditions will allow evolution of earth life, it has happened.
What I am excitingly waiting for is news that one of our robots has successfully penetrated another universe. If so this would confirm that our info cells known as dark matter or energy also could and life as we know it will be.
Outgoing info cells (magnetism)
Incoming info cells (gravity)
This is great! Martin Hirsch, Heinrich Pas and Werner Porod, have indeed glimpsed the perfect (absolute) logic of Space in the oneness of self-contradiction property of Neutrino Physics, beyond the everyday relativity Physics.-Aiya-Oba(Philosopher and discoverer of Nature's absolute logic).
Reply | Report Abuse | Link to thisPlease see comment # 24062 at:
Physics of Life: The dawn of quantum biology:Nature News
http://www.nature.com/news/2011/110615/full//474272a.html
And, Absolute logic the equator of Nature at:
http://en.wikipedia.org/wiki/User:Nuclear_logic
@Quantum Dyslexia
Reply | Report Abuse | Link to this1) Only charged particles interact with photons "on tree level" (that means not considering quantum fluctuations). The interaction of neutrinos and photons via quantum fluctuations is very small and can typically neglected.
2) As a consequence of gravity being described by a tensor field (the metric describing the geometry of spacetime in general relativity is a tensor) masses always attract each other, there is no negative gravity for particles.
Best regards, Heinrich
@Zbyszek: in principle yes, if you assume them to be produced with a defined energy, although a wave picture is more appropriate than the simple particle picture here.
Reply | Report Abuse | Link to thisI read in the article that there are left-handed neutrinos and right-handed neutrinos. I was wondering how the neutrinos are viewed, especially since the earth appears counter-clockwise from the north pole and clockwise from the south pole.
Reply | Report Abuse | Link to this